Erythromelalgia is a disorder that typically affects the skin of the feet or hands, or both, and causes visible redness, intense heat and severe pain. In many cases the use of measures, such as the avoidance of warm temperatures or ongoing elevation required by some with severe erythromelalgia, mean that patients often have to make major adjustments to their lifestyles to avoid flare-ups. The cause of erythromelalgia is unknown in the vast majority of cases, and although a number of medications have been used to help relieve symptoms, there is no single cure available. Erythromelalgia is a rare disease and approximately 15% of erythromelalgia cases have been associated with Nav1.7 gain of function mutations (Dib-Hajj et al (2013) Nature Reviews Neuroscience 14, 49-62; www.ghr.nlm.nih.gov/condition/erythromelalgia).
Thus, there is a need to provide an effective treatment for erythromelalgia to help patients treat their symptoms.
WO 2007/042239 describes 5-(4-{[(2-fluorophenyl)methyl]oxy}phenyl)-prolinamide having the following formula:
and pharmaceutically acceptable salts, solvates or prodrugs thereof.
Themistocleous et al. (2014) Pract. Neurol. 0:1-12 describes that gain of function mutations in Nav1.7 are believed to cause erythromelalgia and paroxysmal extreme pain disorder.